#box{
    width:300px;
    height: 40px;
    position: relative;
    background: #e8e8e8;
    margin:auto;
    border: #e8e8e8 1px solid;
}
#box .btn{
    width:40px;
    height: 40px;
    box-sizing: border-box;
    border:1px solid #eee;
    text-align: center;
    line-height: 40px;
    position: absolute;
    left: 0;
    top: 0;
    z-index: 3;
    font-size: 18px;
    cursor: pointer;
    border: grey 1px solid;
    background-image: url("../images/icon/btn-slider.png");
    background-repeat: no-repeat;
    background-position: center;
}
#box .bg{
    width: 0;
    height: 100%;
    background: #7ac23c;
    position: absolute;
    left: 0;
    top: 0;
    z-index: 1;
}
#box .text{
    width: 100%;
    height: 100%;
    text-align: center;
    position: absolute;
    line-height: 40px;
    z-index: 2;
    font-size: 18px;
    left: 0;
    top: 0;
    margin: 0;
    -webkit-user-select: none;
    -moz-user-select: none;
    -o-user-select: none;
    user-select: none;
}